While cities expand and encroach on the surrounding countryside, nature is being pushed back. These bridges, ladders and byways have been built to enable wildlife to travel safely and freely in an urbanising world

This mini suspension bridge runs above one of Longview, Washington’s main roads. In 1963, local builder Amos Peters became concerned about the number of flattened squirrels on his way to work, so constructed the 60-foot bridge using aluminium and lengths of fire hose

A cougar sits in an outhouse in the Chatsworth Reservoir, Los Angeles. On the city’s outskirts, a multimillion-dollar overpass spanning 10 lanes of the freeway
is being built, to allow these mammals to roam freely in the LA basin. On a US highway, a vehicle hits an animal
every 26 seconds

A beehive on the 12th floor of a building in Oslo, Norway. The city is to create the first ‘
bee highway’ in the world, lined with relays providing food and shelter, to protect these essential but threatened pollinators

A common toad uses an underpass. In Davis, California, tunnels under a six-lane road safely connect amphibians to their breeding ground at a nearby reservoir. The tunnel, which begins in a post office car park was decorated by the postmaster and named ‘
Toad Hollow’

A salmon attempting to leap upstream. At several points along Vancouver’s Capilano River, ‘fish ladders’ have been installed for salmon and trout to migrate. The survival of many species relies on this movement up and down the river

Fallow deer using a bridge to cross the M25 orbital motorway at night. With deer-vehicle collisions estimated at up to 74,000 per year in the UK (with over 450 human injuries), the growth of cities and expansion of road infrastructure calls for bridges and underpasses for the mammals. Photograph:
Jamie Hall

Tracey Adams, a student at Macquarie University found that on Sydney’s roads, almost one possum is killed per day due to population density and increasing urban sprawl. Adams ran a successful campaign for the creation of two trial possum bridges in north Sydney, to allow the mammals to cross the road safely above the traffic

In Anchorage, Alaska, moose were the cause of 106 traffic accidents between 2000 and 2010 on a main route into the city. A fence has been installed lining the highway, directing the animals to a safe underpass on the outskirts of the city. A moose on the pathway at the Ship Creek Underpass, northeast of Anchorage